Wall surface sheet or tile



Patented Sept. 3, 1946 UNITED STATES PATENT OFFICE 2,401,025 WALL SURFACE SHEET on TILE Daniel C. Luse, Chicago, Ill.

No Drawing. Application September 28, 1945,

' Serial No. 619,249

3 Claims. (Cl. 18-475) acter which is fire retarding, moisture resisting.

and highly sound a sor A further object or the invention is to provide a sheet of the above mentioned character which may be cut into desired sizes for forming tile, which can be applied to ceilings and walls for acoustical and sound deadening purposes.

A further object of the invention is to provide a product of the above mentioned character which can be applied to a plastered surface by means of adhesive, or nailed to furrlng strips, or attached to a drop ceiling by metal suspension elements.

A further object of the invention is to provide a tile or product of the above mentioned character which can be spray painted any color for decorative purposes, and which will not lose more than one per cent of its efllciency as a sound absorbing material, even after as many as ten coats of spray painting have been applied thereto.

A further object of the invention is to provide a sheet or tile which is still or rigid whereb it will not warp, nor expand or contract, in service.

A further object of the invention is to provide a sheet or tile of the above mentioned character which can be washed with soap and water without injuring its structural strength, or reducing the sound absorbing qualities.

A further object of the invention is to provide a sheet or tile of sufilcient strength so that all edges can be kerfed for spline insertion in the metal suspension system, and such sheets or tiles having sufiicient strength that they will support themselves on the splines without breaking or fracturing, thereby eliminating any danger of the tiles falling from the ceiling or wall.

A further object of the invention is to provide a sheet or tile for acoustical purposes having an average efficiency equal to .75 noise reduction coeflicient, painted or unpainted, when attached to special metal supports or mounted upon 2"x2" wood furring, and a .85 noise reduction coefllcient when the above mounting is backed by a 2" thick rock wool blanket,

Other objects and advantages of the invention will be apparent during the course or the following description.

The mass or sheet, comprises the constituents of the following ingredients, preferably combined in the proportions stated:

Parts by weight Finely divided or powdered magnesite 9 Finely divided or powdered clay 1% Finely divided or powdered Silax," or finely divided or powdered silica 1% -Finely divided or powdered chalk l Wood wool or fine excelsior, or coarse texture excelsior 12 18 Baum magnesium chloride water solution, or 11 /2 ounces dry magnesium chloride to 1 /2 pints of water 24 The 24 parts by weight of 18 Baum magnesium chloride water solution when computed in ounces will correspond to 11 /2 ounces dry magnesium chloride added to 1 /2 pints of water. The ingredients above given, when the parts by weight are ounces, are suflicient to produce one square toot of the finished sheet or tile. The parts may be in ounces, pounds, or any other units of weight.

In producing the 18 Baum magnesium chloride solution, I employ flake magnesium chloride and add sufllcient water to the same until the water solution of magnesium chloride results in 18 Baum. The water solution of the magnesium chloride is introduced into a receptacle, and the powdered magnesite, clay, "Si1ax and chalk, are added to the magnesium chloride solution and the mass thoroughly mixed or stirred.

The liquid mass thus produced is then introduced into a revolving drum, or other suitable mixing apparatus, and the wood wool or excelsior is added to the liquid mass, while the mass is being stirred or agitated. The stirring is continued until the resultant mass is thoroughly mixed and the wood wool is coated with the liquid mass.

The resultant mass, containing all of the ingredients above referred to, is now removed from the rotating mixing drum, or mixing receptacle, and introduced into flat form or forms. These forms are preferably 36"x72", or larger, but may be smaller, This particular size of sheet, 36"x'72", is important, as this large size sheet may be cut into tiles 0! a size suitable for application to ceilings or walls, without resulting waste. The plastic mass is fed into each form until the mass has a vertical thickness of about 6". When one form is filled, another form is placed on top and filled with the mass to the same vertical thickness, and this is continued until several forms have been filled. After being introduced into each form, the mass is subjected to the action of pressure by means of a hydraulic press or the like until the vertical thickness of the mass is reduced to one inch, or the desired thickness. This thickness can vary in accordance with requirements. A pressure (if-substantially 300 to 500 pounds per square inch may be employed.

After the mass in the forms has been subjected to the action of pressure so that it has a vertical thickness of one inch, or the desired thickness, steel clamps are adjusted so as to hold all the filled forms in position and retain the compressed material in the uniform thickness. After these steel clamps are in place, the pressure from the press is relieved and the forms removed from the press. The clamps retain the pressure of 300 to 500 pounds per square inch upon the mass. There is -no tendency for the mass to increase or decrease in vertical thickness. The mass is allowed to remain in each form for a few hours, preferably from 5 to 6 hours, and the pressure is maintained, which is from 300 to 500 pounds per square 'inch. A chemical reaction occurs between the magnesite and the magnesium chloride, which produces considerable heat, and this chemical reaction may be continued for from 5 to 6 hours,

The heat" and during the pressur treatment. thus produced sufficiently dries or hardens the mass or sheet so that it is set and can be removed from the form'without breakage.

The mass or sheets are then removed from the forms and are placed upon dollies and are rolled into a drying kiln, and are therein subjected to a temperature of substantially 135 F. The mass or sheets may be subjected to the action of other heat, such as heat from electrical means or the like. This heat treatment is continued for a suitable time to drive off all moisture from the "mass, which is rendered rigid and tough. The

heat treatment may be continued for about four to five days, although this time may vary.

After the heat treatment, the mass or sheets are removed from the kiln and are cut to the size required on a saw table.

The product produced by my method is a stiff or rigid mass or sheet, having a cellular construction and resembling in appearance fine sponge rubber, to a certain extent. Due to the porous or cellular formation of the sheet, it has a high noise reduction coeificient. Due to its stiifness, rigidity or strength, the sheet or tile can be nailed to wood furring, or rafters, or held in place by mechanical fastening means, without liability of breakage or subsequent falling from the surface upon which it is applied.

The wood wool, which constitutes the major portion of the mass or sheet, is a fine xcelsior, or an excelsior of a coarser texture. In either case, the strands of wood in theexcelsior may vary somewhat in diameter, but these strands are roughly 2& in diameter and two to ten inches in length. The strands vary somewhat in size and the invention is not restricted to the precise size.

These wood strands may be formed from pine,

spruce or other wood, and they may be formed 'from other plant fibers, such as shredded palm bark. cocoanut fiber, hemp, or other vegetable fiber.-.,

While it is preferred to use 18 Baum magnesium chloride solution, yet the strength of the solution may vary somewhat, depending upon the heat and the humidity, and I may use a magnesium chloride solution of from 17 Baum to 21 Baume.

In the use of the finished sheet or tile, the same may be held in place by any suitable means, as explained. The sheet or tile is porous, fire re- 10 tarding, moisture resisting, non-expanding and non-contracting. The sheet or tile in its natural color and condition, is suitable for ceilings or *walls, without-additional treatment, such as cleaning, painting, etc. However, the sheet or tile will have its decorative appearance improved by painting, which may be done before or after the sheet or tile is placed in position. The painting is preferably effected by spraying the paint upon the sheet or tile. A number of coats of paint may be applied to the sheet or tile without mate- .rially reducing its sound deadening efficiency.

The sheet or tile before or after being painted can be readily cleaned with soap and water, or by a vacuum cleaner, or hair brush, without destroying the structural st ength or impairing the sound deadening qualities. The sheet or tile,

'- when installed upon a ceiling or wall, or suspended from wood furring, or by metal suspension; is highly 'suitable for sound deadening or acoustical correction purposes with a very high percentage of sound absorption. The sheet or tile is unaffected by vermin and will not decay, and will not deteriorate with age. The

sheet or tile in its natural color, may be used for ceilings and walls, as stated.

- The Silax" is used to increase the fire resisting properties of. the product. The powdered chalk serves as a filler and also imparts a lighter color to the product.

40 -Silax" is a trade-mark for silica flour made by F. E. Schundler and Company, Joliet, Illinois.

Satisfactory results have been obtained by using this silica flour. I use finely divided or powdered silica 'and prefer to use this material placed upon the" market under the name of Silax,

' while finely divided silica from any other source maybeused.

Having thus described my invention, what I claimis: 1,. 'T

1; The method of producing a sheet or tile for use as a wall surface, said sheet or tile being rigid, porous, dry and compressed, said method comprising combining approximately 9 parts by weightof finely divided magnesite, approximately 1 /4 parts by weight of finely divided clay. ap-

proximately 1%.parts by weight of finely divided silica, approximately 1-part;by weight of finely divided chalk, and approximately 24 parts by weight of 17 to 21 Baum magnesium chloride .water'solution, mixing the resultant mass for providing a mineral binder, introducing into the mineral binder approximately 12 parts by weight of wood excelsior, mixing the resultant mass, molding the resultant mass, subjecting the molded mass to the action of pressure of approxi- "mately 300 to500 pounds per square inch to increasethe density of the mass, allowing the mass to remain without handling for about 5 to :6 hours so that the chemical reaction between ,k th'emagnesite and the magnesium chloride will produce sufiicient heat to harden the mass so that it may be handled without breakage, and then drying the mass. 7 2. The method of producing a sheet or tile for use as a wall surface, said sheet or tile being {we I rigid, porous, dry and compressed, said method comprising combining approximately 9 parts by weight of finely divided-magnesite, approximately 1%; parts by weight of finely divided clay, approximately 1% parts by weight of finely divided silica, approximately 1 part by weight of finely divided chalk, and approximately 24 parts by weight of 17 to 21 Baum magnesium chloride water solution, mixing the resultant mass for providing a mineral binder, introducing into the mineral binder approximately 12 parts by weight of wood excelsior, mixing the resultant mass, molding the resultant mass, subjecting the molded mass to the action of pressure of approximately 300 to 500 pounds per square inch to increase its density, allowing the mass to remain without handling for about 5 to 6 hours,

6 subjecting the hardened mass to the action of heat at substantially 135 F. for a sufficient length of time to drive 011 substantially all moisture, and then spraying paint upon the dried sheet.

3. A sheet or tile for use as a wall surface, said sheet or tile being rigid, porous, dry and compressed, said sheet or tile comprising the products of reaction of the following ingredients in approximately the proportions stated, 9 parts by weight of finely divided magnesite, 1% parts by weight of finely divided clay, 1% parts by weight of finely divided silica, 1 part by weight of finely divided chalk, 24 parts by weight of a water solution of magnesium chloride of 17 to 21 Baume, and 12 parts by weight of wood excelsior, the sheet or tile being compressed and dried.

DANIEL C. LUBE. 

